Fuel cells electrochemically convert fuels and oxidants to electricity. A Proton Exchange Membrane (hereinafter “PEM”) fuel cell converts the chemical energy of fuels such as hydrogen and oxidants such as air/oxygen directly into electrical energy. The PEM is a solid polymer electrolyte that permits the passage of protons (i.e., H+ ions) from the “anode” side of a fuel cell to the “cathode” side of the fuel cell while preventing passage therethrough of reactant fluids (e.g., hydrogen and air/oxygen gases). The direction, from anode to cathode, of flow of protons serves as the basis for labeling an “anode” side and a “cathode” side of every layer in the fuel cell, and in the fuel cell assembly or stack.
In general, an individual PEM-type fuel cell may have multiple, generally transversely extending layers assembled in a longitudinal direction. In a typical fuel cell assembly or stack, all layers which extend to the periphery of the fuel cells have holes therethrough for alignment and formation of fluid manifolds that generally service fluids for the stack. Typically, gaskets seal these holes and cooperate with the longitudinal extents of the layers for completion of the fluid supply manifolds. As may be known in the art, some of the fluid supply manifolds distribute fuel (e.g., hydrogen) and oxidant (e.g., air/oxygen) to, and remove unused fuel and oxidant as well as product water from, fluid flow plates which serve as flow field plates of each fuel cell. Other fluid supply manifolds circulate coolant (e.g., water) for cooling the fuel cell.
In a typical PEM-type fuel cell, the membrane electrode assembly (hereinafter “MEA”) is sandwiched between “anode” and “cathode” gas diffusion layers (hereinafter “GDLs”) that can be formed from a resilient and conductive material such as carbon fabric or paper. The anode and cathode GDLs serve as electrochemical conductors between catalyzed sites of the PENI and the fuel (e.g., hydrogen) and oxidant (e.g., air/oxygen) which flow in respective “anode” and “cathode” flow channels of respective flow field plates.
A typical fuel cell system generates condensate water at various locations within the system. Therefore, condensate traps have generally been designed and located at these locations to aid in the collection of condensate. The condensate may be collected and stored in a condensate accumulation container for future use by the system.
Whereas, it may be undesirable to allow air to escape through the condensate traps, various arrangements have been designed to prevent air from escaping through the traps. For example, a needle and float arrangement may be utilized to allow condensate to escape when present, however the escape will be plugged when there is no condensate in the trap.
It has been found that undesirable gasses may accumulate in the condensate collection container. Such gasses may become entrained or dissolved in the condensate removed in the system. The gasses may build up in the condensate collection container and present a hazard to the system. For example, a flammable gas such as hydrogen may accumulate in the condensate collection container and present a safety hazard to the system.